Blower

Abstract

A blower is disclosed. The blower comprises an impeller and a scroll housing. The impeller is provided with a plurality of blades and rotated. The scroll housing guides and discharges air sucked by the impeller to the outside, and surrounds the impeller. The expansion angle of the curvature radius of the contour of the scroll housing is designed to be less than an expansion angle in conformity with an Archimedic curve in a suction region ranging from a cutoff start angle to 160-200° from a reference angle. Additionally, the expansion angle of the curvature radius of the contour of the scroll housing is designed to be greater than the expansion angle in conformity with the Archimedean curve in a discharge region ranging exceeding 160-200°.

What is claimed is:  
     
       1. A blower, comprising: 
       an impeller provided with a plurality of blades; and  
       a scroll housing for guiding and discharging air sucked by the impeller to the outside, said scroll housing surrounding said impeller,  
       wherein an expansion angle of a curvature radius of a contour of said scroll housing is designed to be less than an expansion angle α conformity with an Archimedic curve in a suction region ranging from a cutoff start angle to 160-200° from a reference angle being assigned to a position where the contour curve of the scroll housing ends so that the radius of the scroll housing is shorter than that of the Archimedic curve at a position of 180° from the reference angle by a predetermined length L and to be greater than the expansion angle a in conformity with the Archimedic curve in a discharge region range exceeding 160-200° from the reference angle, so that the radius of the scroll housing is longer than that of the Archimedic curve at a position of 360° of the reference angle by almost the predetermined length L.  
     
     
       2. A blower, comprising: 
       an impeller provided with a plurality of blades; and  
       a scroll housing for guiding and discharging air sucked by the impeller to the outside, said scroll housing surrounding said impeller,  
       wherein an expansion angle of a curvature radius of a contour of said scroll housing is designed to be less than an expansion angle in conformity with an Archimedic curve in a suction region ranging from a cutoff start angle to 160-200° from a reference angle being assigned to a position where the contour curve of the scroll housing ends and to be greater than the expansion angle in conformity with the Archimedic curve in a discharge region range exceeding 160-200° from the reference angle, said curvature radius of the contour of the scroll housing is calculated by the following equations:  
       
         
           R θ1 =R o ×(1+θ x ×π/180×tan α 1 )  
         
       
       
         
           R θ2 =[R o ×(1+θ 1 ×π/180×tan α 1 )]×(1+θ x ×π/180×tan α 2 )+{−δ×(θ x −θ 1 )×(θ x −360)} 
         
       
       wherein R o  denotes a radius of said impeller, θ x  denotes an optional angle measured from a reference angle to an optional position past a cutoff start angle along a flow direction, θ 1  denotes a certain angle within an angular range of 160-200°, R θ1  and R θ2  respectively denote a curvature radius in a region where θ x  is equal to or less than θ 1  and a curvature radius in a region where θ x  exceeds θ 1 , α 1  denotes an expansion angle in a region ranging from the reference angle to an angle of θ 1 , α 2  denotes an expansion angle in a region exceeding θ 1 , and δ denotes an optional constant.  
     
     
       3. A blower, comprising: 
       a scroll housing provided with a discharge opening;  
       an impeller positioned in said scroll housing; and  
       guide means, mounted to a side wall of said scroll housing, said guide means being slight in thickness and short in height at a portion near said impeller, and increasing in thickness as it projects toward said discharge opening, having a final height approximately equal to the height of the discharge opening.  
     
     
       4. The blower according to  claim 3 , wherein said guide means has a curved portion in the vicinity of said impeller and maintains said curve as it is gradually projected toward the discharging opening of said scroll housing from the curved portion. 
     
     
       5. The blower according to  claim 4 , wherein said blower consists of two sub-blowers and said guide means consists of two discharge guides, said sub-blowers being positioned at both sides of a motor, said discharge guides being respectively mounted to outer sides of discharging openings of said sub-blowers. 
     
     
       6. The blower according to  claim 3 , wherein a maximum projected width of said guide means is less than 20% of a length of said scroll housing. 
     
     
       7. The blower according to  claim 6 , wherein a maximum projected width of said guide means is 5-15% of a length of said scroll housing. 
     
     
       8. The blower according to  claim 6 , wherein said blower consists of two sub-blowers and said guide means consists of two discharge guides, said sub-blowers being positioned at both sides of a motor, said discharge guides being respectively mounted to outer sides of discharging openings of said sub-blowers. 
     
     
       9. The blower according to  claim 7 , wherein said blower consists of two sub-blowers and said guide means consists of two discharge guides, said sub-blowers being positioned at both sides of a motor, said discharge guides being respectively mounted to outer sides of discharging openings of said sub-blowers. 
     
     
       10. The blower according to  claim 3 , wherein said blower consists of two sub-blowers and said guide means consists of two discharge guides, said sub-blowers being positioned at both sides of a motor, said discharge guides being respectively mounted to outer sides of discharging openings of said sub-blowers.